Rooe structure



Nov. 22, 1927. R 16,798

H. E. MARKS noor' sTRiJcTURE Original Filed Aug. 31. 1 20 Maw ATTORN EYSReissued Nov. 22, 1921.

UNITED. STATES HERBERT E. MARKS, F GLEN OSBORNE, PENNSYLVANIA.

ROOF STRUCTURE.

Original I0. 1,398,079, dated November 22, 1921, Serial No. 407,189,filed August 31, 1920. Divided and this application for reissue filedThis invention relates to roof structures. Its object is to provide aroof structure which is fire-proof, which forms an eflicient heatinsulator, which is light in weight, low

in cost, which can be easily and cheaply erected, and which,nevertheless, is strong and durable. This application constitutes adivisional reissue application based on my reissue application SerialNo. 62,677, filed October 15, 1925, for the reissue of Letters PatentNo. 1,398,079.

Generally stated, heinvention comprises a roof structure containingmetallic angle members and a substantially monolithic and reinforcedslab of gypsum or similar material, combined and assembled in the novelway hereinafter described.

In the accompanying drawings Figure 1 is a vertical section of aninclined roof con 29 structed in accordance with the invention; Figure 2shows a portion of Figure 1 on an enlarged scale; and Figure 3 is a.section taken on line 3, 3 of Figure 2 on a still larger scale.

The invention is applicable to a roof of any type, and in the drawingsis shown as applied in a double sloping or ridge roof. In the drawings 1indicates a suitable frame truss or part of the building on which the 30roof is supported and 2 indicates purlins for supporting the roofstructure proper. of these parts are illustrated as formed of structuralsteel, and obviously can be of any material, character or design,depending upon the kind and size of the roof.

The roof structure proper comprises a plurality of angle bars,specifically of the type known as T-bars, 3, which rest with their baseflanges upon the purlins and are suitably secured thereto and with theirlegs projecting upwardly. These T-bars form the base for the roofstructure proper and will be spaced suificiently close that the distancetherein can be bridged by ordinary sizes of plaster or gypsum boards,which are articles of commercial manufacture and sale, being generallycomposed of molded gypsum or the like, and generally are uite thin,usually about three-eighths of an inch in thickness. The plaster orgypsum boards are shown at 4, having their side edges resting upon andsupported by the horizontal flanges 5 of the T-bars 3, as shown in Fig.3. These gypsum boards can be chosen of any suitable length, butpreferably of a length ing across,

January 2, 1926. Serial No. 79,058.

substantially equal to the space between adjacent purlins 2, but insteadof extending from purlin to purlin they are so placed that their centralportions are substantially above purlins, with their end portionsmeeting about midway between adjacent purlins. To support the endportions of these plaster boards it is preferred to use small anglemembers 6, of a length equal to the distance between adjacent T-bars 3,and having their ends resting upon the flanges 5 of said' T-bars, as aresult of which the thin laster boards are supported not only at theirside edges but also at their end edges. Obviouslyin lieu of the T-bars3, a pair of angle bars or channels placed back to back may be utilized,and likewise instead of the angle bars 6 placed back to back as shown,small T-bars or channels may be used.

The plaster boards 4, placed in the manner described, serve as centeringfor the formation of the roof slab, and also as the lower facing of theroof slab. The roof slab is formed from suitable cementitious material,such as gypsum, which is mixed with the proper proportion of water andthen molded directly in place, that is, by being poured upon thecentering formed by the plaster boards 4. The composition of thiscementitious material is preferably the same as 11 that of the plasterboards but in any event is of such nature that when poured in place itbonds onto the plaster boards so that the latter and the solidifiedcementitious material form a unitary or monolithic slab.

Preferably this slab will be reinforced by embedding in the cementitiousmaterial suitable metallic reinforcement 7 preferably a metallic mesh,such as metallic lath, wire mesh, or the like. This metallicreinforcement may be in the form of sheets extendand resting u on theupper ed es of the angle bars 6 and supported y ein the latter andthereby properly spaced from the plaster boards 4,the upward projectionof the angle bars 6 preferably being somewhat greater than the thicknessof the plaster boards, but terminating below the center of the upwardlyprojecting leg of the T-bars, so that the metal reinforcement will beembedded close to the lower face of the slab. This metallic mesh will beeither one continuous strip extending from the eaves to the ridge of theroof, or may be composed of a number of pieces,

the ends of which are 11 overlapped so that when embedded in thecementitious material it has the same reinforcing effect as though acontinuous strip of material were used; also if desired, the edgeportions of the'metallic reinforcement may be bent upwardly and made tooverlap the upper edges of the T bars 3, as shown at 8, Fig. 3, so as toalso secure a continuous, additional transverse tie; or the strips ofreinforcement ma run across the T bars 3, and bend down between theT-bars, with their edges overlapping to give in eflect a .continuousreinforcement, when embedded in. the cementitious material, from eave tomuch as the entire ridge and also transversely of the roof. Thecementitious material whlch is poured onto the centering plaster boards4 readily passes through this metal mesh and bonds to the laster boards.Such material will be filled in to a depth somewhat greater than that ofthe T-bars 3 so that no portion of the metal frame is exposed on the topsurface.

The roof structure described is of simple construction, is easy andcheap to construct, is light, and with all is very strong, masstructure,including the plaster boards, forms a monolithic slab which isreinforced for its entire length and width, and is, therefore, capableof standing a ver considerable loa This slab 1s reinforced not only bythe metal mesh described, but also by the T-bars 3 andangle bars 6 whichbecome thoroughly embedded and bonded in the cementitious material. Theconse uence is that the metal members can be of ight cross section, andthe slab of minimum thickness.

Since the plaster boards which form the bottom surface of this slabserve as center- .ing, the usual centering for erecting roofs of thiskind can be entlrely dispensed with, thus making agreat saving in costof erection.

The to surface of this roof structure will be suita ly water-proofed byany of the usual water proofing methods, such as by applying thereto acoating of asphaltum or the like, and can be finished in any desired wayof finishing roofs of this kind, such 'as by providing the same with agravel or other sur ace.

In case the cementitious material is such as to form a strong slab, suchas cement, the members 4 need not necessarily be of a composition tobond with the cementitious material, but may be the so-called commercialbeaver board or the like thin board.,

I claim: 1. The method of making a roof of the character describedincluding purlins which consists in laying supporting members acrosssaid purlins, laying plaster boards between said supporting members sothat they rest thereon and form centerin and bringing into cooperativerelation with said plaster boards, means for holding adjacent transverseedges of the same substantially in alignment with each other while theyserve as centering; and molding onto the plaster boards a cementitiousmaterial which bonds therewith, thereby forming a monolithic roof slabincluding the plaster boards, cementitious material and the means forholding adjacent transverse edges of the plaster boardsin alignment.

2. The method of making a roof of the character described includingpurlins which consists in laying supporting members across said purlins,laying plaster boards of ordinary commercial size between saidsupporting members so that they rest thereon, and bringing strengtheningmeans into such cooperative relation with the plaster boardsthatthe'boards are rendered capable of carrying the weight of a plasticmass of cementitious material without excessive deflection, the saidmeans being adapted to form a permanent part of the finished roof;placing metal reinforcin fabric over said supporting members and inspaced relation to said plaster boards, and molding a cementitiousmaterial onto the plaster boards to a depth greater than said supportingmembers, whereby a monolithic roof slab is formed, comprising theplaster boards, cementitious material, metal reinforcement and saidstrengthening means.

3. The method of making a roof of the character described includingpurlins which consists in laying supporting members across said urlins,layin substantially rectangular p aster boards ietween said supportingmembers so that one pair of opposite edges of each of said boards issupported by said members, maintaining the other pair of o posite edgesof each of said plaster boar s in substantially aligned relation bysupporting said edges from angle members extending between th supportingmembers, laying metal reinforcin fabric over said supporting members andin spaced relation to said plaster boards, and'molding a cementitiousmaterial onto the plaster boards to a depth greater than said supportinmembers, whereby a monolithic roof sla is formed, comprising the plasterboards, cementitious" material and metal reinforcement.

4. The method of making a roof of the characterdescribed includingpurlins which consists in laying on said purlins metal an le memberspresenting op ositely projectln flanges, laying on'said anges small metaangle members and plaster boards, the small metal angle members alsopresenting opposltely projectin flanges, said boards havlng one pair ofsi e edges resting on the first named angle member and another pair ofside edges resting on the flanges of the small metal angle members; andmolding a cementitious material onto the plaster boards to bondtherewith and to extend above the first named angle members, therebyforming a monolithic roof slab.

5. The method of making a roof of the character described includingpurlins which consists in laying supporting members across said purlins,laying plaster boards of ordinary commercial size and strengtheningmeans between said supporting members so that they rest thereon, thestrengthening means being arranged in such cooperative relation with theplaster boards that the boards are rendered capable of carrying theweight of a plastic mass of cementitious material without excessivedeflection, the said means being adapted to form a permanent part of thefinished roof; and molding a cementitious material onto the plasterboards to a. depth greater than said supportin members, whereby amonolithic .roof sla is formed, comprising the plaster boards,cementitious material and said strengthening means.

In testimony whereof I aflix my signature.

HERBERT E. MARKS.

